A computer is usually equipped to use a "mouse" for movement of a cursor and initiating other functions of the computer. It is oftentimes, however, fatiguing to the operator to use a mouse repeatedly over the course of a day which can result in severe physical strain. Further, specialized equipment has been developed for left versus right-handed computer operators using a mouse. This can add expense to a manufacturer and a retailer to stock a left-hand use mouse and a right-hand use mouse.
An alternate system for controlling movement of a cursor is by the use of a track ball. Oftentimes mounted in front of or to one side of a keyboard, a roller ball of the track ball is rotated to shift a cursor.
The use of a mouse or track ball are alternative systems for controlling a single cursor. Therefore, two pieces of equipment are required if an operator desires the ability to switch back and forth between a track ball and a mouse.